The control of the content is important in order to protect the programming from, for example, nonpaying customers. A conventional communications system, such as a cable television system, therefore, typically applies an encryption scheme to television content in order to prevent unrestricted access. Once a system operator chooses an encryption scheme, the operator installs all of the necessary headend equipment (e.g., Scientific-Atlanta's conditional access software and equipment). The devices (set-tops) located at the subscriber's premises must be compatible with the encryption scheme in order to decrypt the content for viewing. Due to the proprietary systems, however, an operator is prevented from installing different set-tops that do not have the proper decryption scheme. If the operator wishes to install different set-tops that decrypt a different conditional access system, the operator would also have to install a second proprietary system to overlay the incumbent system in order to use both boxes.
It would be to the operator's advantage to be able to choose boxes from any manufacturer and easily implement different encryption schemes in the system without duplicating the headend equipment and utilizing extra bandwidth. Some have attempted to address a technique that overlays two encryption schemes in a system. The present application is directed towards improvements to and alternative embodiments of a conditional access system that enables different proprietary set-tops that decrypt content that has been encrypted by different encryption schemes.